Question

我想从gridpane中删除fxml（作为新列添加）。现在，在单击按钮后，方法 addNextToCompare 将一列添加到 mainGridPaneCarCompare ，并在该位置插入来自FXMLLoader的新fxml。

在我的 deleteColumn 方法中，我尝试了 mainGridPaneCarCompare.getChildren（）。removeAll（...）; 但它返回空指针异常。方法 getChildren.clear（）在mainGridPane中留下空白区域。我的计划从一开始就错了吗？我应该创建fxml的 List 并分别删除项目吗？

主要课程：

public class Main extends Application {
public static void main(String[] args) {
    launch(args);
}

@Override
public void start(Stage primaryStage) throws Exception {
    try {
        FXMLLoader loader = new FXMLLoader(this.getClass().getResource("/resources/mainScene.fxml"));
        new GridPane();
        GridPane tempGridPane;
        tempGridPane = loader.load();

        Scene scene = new Scene(tempGridPane);
        primaryStage.setScene(scene);
        primaryStage.show();

    } catch (Exception e) {
        System.out.println(e);
        e.printStackTrace();
    }
}

}

fxml的控制器：

public class Controller {
@FXML
private GridPane mainGridPaneCarCompare;
@FXML
private AnchorPane addCarAnchorPane;
@FXML
private Button addCarButton;
@FXML
private GridPane nextColumnGridPane;
@FXML
private void initialize() {
}
@FXML
public void addNextToCompare() {
    //move anchorPane with button addNextCar one column to right
    if (GridPane.getColumnIndex(addCarAnchorPane) < 4) {
        GridPane.setColumnIndex(addCarAnchorPane, GridPane.getColumnIndex(addCarAnchorPane) + 1);
    } else {
        addCarButton.setDisable(true);
    }
    //load new fxml
    FXMLLoader loader = new FXMLLoader(this.getClass().getResource("/resources/scene2.fxml"));
    GridPane temporaryGridPane = new GridPane();
    try {
        temporaryGridPane = loader.load();
    } catch (Exception e) {
        System.out.println(e);
    }
    //insert nextCarCompareWindow.fxml
    mainGridPaneCarCompare.add(temporaryGridPane, GridPane.getColumnIndex(addCarAnchorPane) - 1, 0, 1, 6);
}

@FXML
public void deleteColumn() {
    try {
        System.out.println("inside nextgridcarcompare: " + nextColumnGridPane.getChildren());
        nextColumnGridPane.getChildren().clear();
    } catch (Exception e) {
        System.out.println(e);
    }
}

}

MainScene.fxml：

<GridPane fx:id="mainGridPaneCarCompare" gridLinesVisible="true" hgap="5.0" vgap="5.0" xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
  <columnConstraints>
      <ColumnConstraints prefWidth="250.0" />
      <ColumnConstraints />
  </columnConstraints>
  <rowConstraints>
      <RowConstraints prefHeight="200.0" />
      <RowConstraints prefHeight="50.0" />
      <RowConstraints prefHeight="180.0" />
      <RowConstraints prefHeight="150.0" />
      <RowConstraints prefHeight="150.0" />
      <RowConstraints prefHeight="100.0" />
  </rowConstraints>
  <children>
      <AnchorPane prefHeight="200.0" prefWidth="250.0">
          <children>
              <ImageView fitHeight="140.0" fitWidth="220.0" layoutX="15.0" layoutY="22.0" pickOnBounds="true" preserveRatio="true" />
              <HBox layoutX="15.0" layoutY="170.0" spacing="5.0">
                  <children>
                      <Button mnemonicParsing="false" text="Change car" />
                      <Button mnemonicParsing="false" text="Edit" />
                  </children>
              </HBox>
              <Label fx:id="selectedCarLabel" layoutX="102.0" layoutY="5.0" text="Title" />
          </children>
      </AnchorPane>
      <AnchorPane fx:id="addCarAnchorPane" GridPane.columnIndex="1">
          <children>
              <Button fx:id="addCarButton" layoutX="96.0" layoutY="87.0" mnemonicParsing="false" onAction="#addNextToCompare" text="Add car" AnchorPane.bottomAnchor="88.0" AnchorPane.leftAnchor="96.0" AnchorPane.rightAnchor="97.0" AnchorPane.topAnchor="87.0" />
          </children>
      </AnchorPane>
      <AnchorPane prefWidth="250.0" GridPane.rowIndex="1">
          <children>
              <ListView prefWidth="170.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
          </children>
      </AnchorPane>
      <AnchorPane GridPane.rowIndex="2">
          <children>
              <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
          </children>
      </AnchorPane>
      <AnchorPane GridPane.rowIndex="3">
          <children>
              <ListView layoutY="177.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
          </children>
      </AnchorPane>
      <AnchorPane GridPane.rowIndex="4">
          <children>
              <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
          </children>
      </AnchorPane>
      <AnchorPane GridPane.rowIndex="5">
          <children>
              <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
          </children>
      </AnchorPane>
  </children>
</GridPane>

SecondScene.fxml

<GridPane fx:id="nextColumnGridPane" accessibleRole="NODE" gridLinesVisible="true" hgap="5.0" vgap="5.0" xmlns="http://javafx.com/javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
<columnConstraints>
    <ColumnConstraints prefWidth="250.0" />
</columnConstraints>
<rowConstraints>
    <RowConstraints minHeight="-Infinity" prefHeight="200.0" />
    <RowConstraints prefHeight="50.0" />
    <RowConstraints prefHeight="180.0" />
    <RowConstraints prefHeight="150.0" />
    <RowConstraints prefHeight="150.0" />
    <RowConstraints prefHeight="100.0" />
</rowConstraints>
<children>
    <AnchorPane>
        <children>
            <ImageView fitHeight="140.0" fitWidth="220.0" layoutX="15.0" layoutY="22.0" pickOnBounds="true" preserveRatio="true" />
            <HBox layoutX="15.0" layoutY="170.0" spacing="5.0">
                <children>
                    <Button fx:id="deleteButton" mnemonicParsing="false" onAction="#deleteColumn" text="Delete" />
                    <Button mnemonicParsing="false" text="Change car" />
                    <Button mnemonicParsing="false" text="Edit" />
                </children>
            </HBox>
            <Label layoutX="102.0" layoutY="5.0" text="Title" />
        </children>
    </AnchorPane>
    <AnchorPane GridPane.rowIndex="1">
        <children>
            <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
        </children>
    </AnchorPane>
    <AnchorPane GridPane.rowIndex="2">
        <children>
            <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
        </children>
    </AnchorPane>
    <AnchorPane GridPane.rowIndex="3">
        <children>
            <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
        </children>
    </AnchorPane>
    <AnchorPane GridPane.rowIndex="4">
        <children>
            <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
        </children>
    </AnchorPane>
    <AnchorPane GridPane.rowIndex="5">
        <children>
            <ListView AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="80.0" AnchorPane.topAnchor="0.0" />
        </children>
    </AnchorPane>
</children>
</GridPane>

这是我的第一篇文章，我希望，我能清楚表达自己。感谢您的任何建议：）

JavaFX删除gridpane中的列

0 个答案: